1. Field of the Invention
The present invention relates to pressure release valves and more particularly to a novel, highly advantageous low pressure vent which may be utilized in systems for handling and storing pressurized fluids or gases, such as oxygen, in containers.
2. Related Art
Gas delivery systems typically consist of a pressurized gas filled container utilizing a regulator connected to a post valve of a container, such that gas will depart the container through the post valve and enter the regulator. The regulator releases a constant flow of gas into its desired destination, such as an oxygen mask, at a user selected level. When the post valve is closed which disrupts the flow of pressurized gas from the container, gas that has already left the container may become trapped between the post valve and regulator in a valve chamber of the regulator. When the regulator is subsequently disconnected from the post valve, the trapped gas which may be highly pressurized is released rapidly into the atmosphere. This rapid release of certain gases can be dangerous, such as when the container is filled with oxygen gas and combustible materials, such as plastic tubing, come in contact with the gas.
Pressure release valves prevent combustion by bleeding trapped gas out of the valve chamber. Pressure release valves are highly desirable in medical oxygen systems, including systems for patient home use, to bleed off pressurized oxygen that might otherwise have a potential for danger or pose a risk, such as by igniting combustible material. However, pressure release valves are not frequently incorporated within valve assemblies because of the difficulty of installation and the size constraints of the valve assembly.
Pressure release valves are impractical to implement in the limited space of a small valve chamber, such as may be found in a regulator. Existing pressure release valves are presently known to incorporate a poppet to seal and unseal a valve chamber and thereby selectively release pressurized gas. A spring pushes a cone of the poppet against an inner surface of the valve chamber thereby securing the poppet and sealing the valve chamber.
Incorporating a pressure release valve into a valve chamber of a regulator at the time of this invention has been impractical because suitable springs are difficult to design and install. Springs of approximately one-quarter of an inch are difficult to manufacture and are cost prohibitive to incorporate into a regulator design. Further, it is difficult to compress small springs evenly into small valve assemblies. Moreover, the addition of such small springs, which may be prone to breakage due to workmanship or incorrect installation, may compromise the reliability of the valve. These difficulties have made the design of a springless pressure relief valve desirable.
Accordingly, among the several objects, features and advantages of the invention may be noted the provision of a pressure relief valve which is springless, which has a simple design, requiring a minimum number of parts, and is easy and quick to install. It is a further feature and advantage that this pressure release valve is, because of its springless nature, inherently extremely compact.
The resilient yet compressible cone is a significant improvement over the known art. Pressure release valves typically use springs between a cone and a valve chamber for compression. These pressure release valves are difficult to install in small applications, such as on a flow selector, where there is inadequate room to utilize a spring. Also, in such small applications, there is difficulty in positioning the spring so that it does not compress awkwardly and favor one direction over another. The installation of the novel poppet is quick and reliable, and requires no spring aligning.
Briefly, the invention relates to improvements in pressurized gas flow control devices. Such a device may include a pressurized gas control body in which pressurized gas is provided from a pressurized source. The flow control device can selectively connect or disconnect a pressurized gas flow connection to the control body. More specifically, the improvement relates to such a springless pressure relief device incorporated integrally into the flow control. The relief device relieves gas pressure within the control body before connecting or disconnecting the flow connection. The relief device has a valve member movable within a valve member chamber and juxtaposed between a rigid surface of the chamber and a seat for the valve member, which is normally sealed by the valve member. The seat of the valve member communicates exteriorly of the control body. The chamber communicates with the control body for receiving gas pressure within the control body. The valve member is formed at least in part of a resilient material which is maintained in contact with the rigid surface so as to urge the valve member along said axis in a direction against said seat for providing the normal sealing relationship. The resilient material is compressible, however, so that the valve member can be selectively shiftable by compressing the resilient material along the axis toward the rigid surface for unseating of the valve member from the seat. Such shifting unseats the valve member from its seat to vent pressurized gas pressure exteriorly of the pressurized gas control body.
Other objects, features, and advantages will be apparent or are point out more particular herein below.